After building the mini pedal exerciser, I decided to go further. I added a motor to act as a generator to charge my batteries. Stepper motors can be found almost anywhere, specially in printers. Cut a 10 inch diameter wood, added a rubber shaft to the servo motor, reconfigured the wirings, and attached to the exerciser.
Putting the generator into operation. Recharging the 12 volts nickel cadmium batteries. The more you pedal the more you sweat, and the more output you give off to your batteries.
Different looks of stepper motors.
Diagram of the 6 pole motor with added 4 each 1N4004 diodes and 1000uf capacitor